1. Field of the Invention
This invention relates to an improvement in a car door lock system.
2. Description of the Related Art
In recent years, as car door lock systems, so-called two-stage door lock systems with which a key cylinder is unlock-operated and then a door is unlocked by an operating lever being unlock-operated have been widely used. A car door lock system of this kind is disclosed for example in Japanese Utility Model Publication No. HEI-5-32605.
In this lock system, by unlocking a key cylinder and inclining a bell crank connected to the end of a rod, a long and thin plate-like opener lever connected to the bell crank is moved horizontally and then an outer handle 6 is operated to incline the opener lever and a lock device mounted at the lower end of the rod is thereby disengaged from a striker to open a back door.
In this lock system, the striker is mounted to the vehicle body and all of the rest of the lock mechanism is mounted to the back door.
However, when the door is small, there are space restrictions on mounting many lock mechanisms to the door. For this reason, it would be preferable for the striker to be mounted to the door and for the lock mechanisms to be mounted to the vehicle body.
However, generally, in order to open the door of a vehicle with one hand, the door is opened while the outer handle is being operated. Consequently, if the outer handle is mounted to the vehicle body the operation of opening the door becomes more difficult.
Considering this point, it is conceivable to mount the striker and the outer handle to the door and mount the rest of the locking mechanism to the vehicle body; however, because it then becomes impossible to connect the outer handle to the locking mechanism with a rod, this configuration is mechanically unworkable.
Consequently there has been a need for a two-stage type door lock system with which it is possible to open a door easily with one hand by performing an unlocking operation on the door side after unlocking a key cylinder mounted on the vehicle body side.